Stock Ledger Issue - Inventory costing for Zero Cost item

Dear ALL,

We’ve got an issue with an item in our Stock with zero cost upon receipt from Supplier(items given for free by supplier).
Below is the screenshot for reference:

As per above screenshot, it is showing that before the item was received with Zero Cost, the initial qty is Zero and last purchase amount is 65AED.

Upon receiving the same item on the following day at zero rate, it automatically get the previous rate which is 65aed upon viewing the stock ledger.

This item should show Zero cost for 5 units, right?
and upon sale, the cost should also be Zero, but now it is showing different amount arising to a negative GP since the cost is showing even higher rate than that the normal purchasing price.

Thank you…